PROJECT SUMMARY/ABSTRACT Adolescence and HIV SWG (SWG_2) In the United States, approximately 26% of all incident HIV infections annually have involved adolescents and young adults aged 13-24. Internationally, the World Health Organization estimates that every two minutes an adolescent aged 15-19 acquires HIV. Adolescents are key drivers of the HIV epidemic both globally and in the United States, highlighting the urgent need to implement efficacious prevention programs, youth-friendly testing services, and care programming that promotes long-term engagement in care with achievement of sustained viral suppression and thus avoidance of drug resistance. Despite the availability of effective treatment options, AIDS remains one of the leading causes of death among adolescents worldwide, highlighting the challenges of engaging adolescents with HIV in sustained care, in some cases, for decades beginning in early infancy. Furthermore, failure to engage sexually active adolescents with HIV in care and promote sustained viral suppression increases population risk of HIV acquisition and promotes transmission of resistant HIV viral strains. Providing the best possible HIV prevention and care and treatment services for adolescents requires a wide range of setting-specific, youth-responsive approaches. Current research by Harvard University Center for AIDS Research (HU CFAR) investigators includes a broad scope of prevention, testing, and care approaches for adolescents at risk for HIV and those living with HIV and complications of HIV disease and treatment. We propose to develop an Adolescence & HIV Scientific Working Group (SWG) within the HU CFAR to bring these investigators together, with three specific aims: 1) To promote participation in adolescent-focused HIV prevention and care research from a broad community of investigators and public health organizations; 2) To develop a novel adolescent HIV research ?tool kit,? building on the expertise of HU CFAR investigators to provide methodologic resources for investigators new to adolescent HIV; 3) To create and support new mentorship relationships and new adolescent HIV-focused research projects, expand the HU CFAR adolescent HIV research portfolio, and increase the number of Early Career Investigators funded to conduct adolescent HIV work. By creating an Adolescence & HIV Scientific Working Group, we plan to promote interdisciplinary engagement in adolescent-focused HIV research, provide adolescent-specific methodologic resources, and expand the HU CFAR portfolio of adolescent-centered research. Leveraging the strengths of the Harvard University CFAR and the broader CFAR and Boston scientific communities, we will catalyze new collaborations, with particular emphasis on promoting Early Career Investigators and partnerships with DPH. The HU CFAR Adolescent & HIV SWG can thus generate innovative approaches to critical questions impacting a key vulnerable population: adolescents and young adults with HIV and at risk of HIV.